Drying kiln



D. 8: J. S. HILL.

DRYING KILN.

No. 589,895. Patented Sept. 14,1897.-

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D. 817 J'. S. HILL.

DRYING KILN.

No. 589,895. Patentd Sept. 14,1897.

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DRYING-KILN.

$PEGIFICATION forming part of Letters Patent No. 589,895, datedSeptember 14, 1897. Application filed December 16, 1896. Serial No.615,921. (No model.)

To on whom it may concern:

Be it known that we, DAVID "HILL-and' JAMES S. HILL, citizens'of theUnited States, residing at Washington, in the county of Beaufort andState of North Carolina, have invented certain new and usefulImprovements in Drying-Kilns and we do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art towhich it appertains to make and usethe same.

Our invention is an improvement in dry lug-kilns adapted especially fordrying lumber; and it consists in the novel features hereinafterdescribed, reference being had to the accompanying drawings, whichillustrate our invention, and said invention is fully dis closedin thefollowing description and claims.

Referring to'the said drawings, Figure 1 represents a transversevertical sectional View of a kiln embodying our invention. Fig. 2 is alongitudinal vertical sectional view of the same. Fig. 3 is a viewsimilar to Fig. 1, show ing a slight modification. Fig. 5 is atransverse sectional view of 'a'form of eduction tube which we mayemploy. Fig. at is alongitudinal sectional view similar to Fig. 2,showing a slightly-modified form of kiln. Fig. 5 is a transversesectional View of the same. Fig. 6 is a horizontal sectional view of aportion of the same. Fig. 7is a horizontal sectional view of anotherportion of the kiln.

I11 the form of our invention shown in Figs. 1 and 2,A represents thekiln provided with a drying-chamber B, which is hermetically sealed atthe bottom and sides and at the top is provided with one or moreexit-fines or chimneys C, one being shown. The dryingchamber 13 isprovided with the usual inclined track 1), upon whichtrucks carrying thelumber can be rolled into and out of the kiln, which isclosed at eachend by a sliding door I) of any usual or preferred construction. In thebottom of the drying-chamber is a heating-coil consisting in thisinstance or a central pipe D, provided with lateral branches d d,through which steam is passed for heating the drying chamber and thelumber. WVe provide means for removing from the dryingchamber themoisture which isdriven out by the heating device in the form of vapor.In these figures we have shown an eduction-pipe E extending alongthe topof the drying-chamber above the lumberfor the entire length of the kilnand provided with lateral branch pipes e e on each side. The main pipe Eand the branches 6 e are all provided with perforations or holes toadmit the vapor into the pipes, and at one end the main tube E isconducted up the flue C, where it is provided with asuitable exhaust. Inthis instance we SllOW the tube E formed with an exhaust-fan E, butother forms of exhausting devices may be used, if preferred.

The operation of the kiln is as follows: The green lumber is placed inthe kiln, the doors closed, and steam admitted to the steam-coil. Theheat in the drying-chamber causes the moisture inthelumber to slowlyvaporize and pass to the top of the drying-chamber. The exhaustingdevice (operated by a belt from any suitable source of power) will suckthe vapor into the eduction pipe E and its branches and discharge itthrough the top of the stack or fine 0. In'this way the moisture isremoved-from thedrying-chamber as rapidly as it is driven'out of thelumber and there is no opportunity forit to get back again. The lumbercannot mildew or blue, and there is very little heat lost from thedrying-chamber. Hence it is a very economical kiln to operate.

In Fig.3 we have shown a slight modification of this form'ofjkiln, inwhich vertical airpassages a care provided at each side of thedrying-chamber, which communicate therewith at the top of said chamber.In this instance a series of inlet-apertures a a are provided adjacentto the bottom of the kiln to admit air between the outer wall of thekiln and the wall of the drying-chamber. These apertures are controlledby suitable valves a a so that they can be closed, if desired. lVhenthey are open, the air enters through apertures a a, ascends thevertical passages a. a, and passes over the top of the lumber, where itabsorbs themoisture and is sucked or forced out through theeduction-pipe E. In Fig. 3 we show another form of eductionpipe whichmay be employed, the same consisting of a box E polygonal inconstruction, having its bottom provided with perforations through whichthe moist vapor or the air and vapor is drawn.

We provide this form of kiln (shown in Figs. 1, 2, and 3) with means forresisting fire, which consists in this instance of a waterpipe F,connected to the end of the eductionpipe farthest from the exhaust andprovided with a valve f. In case of fire the exhaust is stopped and thevalve f is turned on, thus filling the pipe E and branches with water,which flows in a shower through the apertures therein and floods thelumber, thus putting out the fire. The danger of fire is, however, veryslight, as the drying-chamber when in operation contains very little airto support combustion and the moist vapor above the lumber would tend toprevent a flame from starting.

In Figs. 4 to 7, inclusive, we have shown another slightly-modified formof kiln embodying our invention. In these figures, A represents thekiln; B, the drying-chamber, sealed at bottom and sides, as previouslydescribed, and communicating with the stack 0 at the top. G representsthe heating-coil, constructed as previously described. H represents theeduction-pipe, with branches h, as previously described, and IIrepresents a steam-pipe which passes up through and dischargesvertically in the portion of the pipe in the stack C so as to serve asan exhaust in place of a fan to draw out the moisture from the top ofthe drying-chamber. This pipe II we preferably connect with the exhaustof a steam-engine; but it may be operated with live steam, if preferred,or a fan may be substituted for it, as in Figs. 1, 2, and 3. Irepresents an air-pipe which preferably passes longitudinally throughthe kiln at the bottom adjacent to the heating-coil and then passesupwardly and communicates with the eduction-pipe at the end farthestfrom the exhaust. The effect of the exhaust is therefore to draw in airthrough the airpipe I, which is warmed by reason of its nearness to theheating-pipes and draws the warm air into the eduction-pipe, where itabsorbs the moist vapor, also drawn into the eduction-pipes, and thewhole is then discharged through the stack. In order to regulate theair-supply, we provide the pipe I with a cock '0' outside of the kiln.We prefer to connect the air-pipe I with both the steam-pipe g for thesteam-coil and the exhaust-pipe H by means of pipes t" and F, providedwith valves '6 i the said steam and exhaust pipes being provided withcut-off valves and W, respectively. By this means we can close thevalves g and h and open valves 2' t and fiood the entire kiln with livesteam in case of fire. We may also run a branch pipe K from the rear endof the eduction-pipe 1 1 outside the kiln and connect with it awatersupply pipe L, provided with a cock Z, as shown in Fig. 7, so thatthe lumber can be flooded with water should it become necessary.

What we claim, and desire to secure by Letters Patent, is-- 1. In adrying-kiln, the combination with a dryin g-chamber sealed at its bottomand sides, and having a discharge-passage communicating with the top ofsaid chamber, of a heating device in said chamber, and means for positively removing aqueous vapor from said chamber through saiddischarge-passage, substantially as described.

2. In a drying-kiln, the combination with a drying-chamber sealed at itsbottom and sides, and having a discharge-passage communicating with thetop of said chamber, of a heating device adjacent to the bottom of saidchamber and an exhausting device communicating with saiddischarge-passage, substantially as described.

3. In a drying-kiln, the combination with the drying-chamber sealed atits bottom and sides, of a heating device adjacent to the bottom of saidchamber, means for admitting air to said chamber adjacent to its top,and an air-exhausting device for removing air from said chamber adjacentto its top, substantially as described.

1. In a drying-kiln, the combination with the'drying-chamber, sealed atits bottom and sides, of a heating device adjacent to the bottom of saidchamber, an eduction-pipe provided with a series of apertures adjacentto the top of the chamber, an exhausting device connected with saideduction-pipe, and a water-pipe connected with said eduction-pipe, andprovided with a controlling-valve, where by the contents of thedrying-chamber may be flooded in case of fire, substantially as described.

5. In a drying-kiln, the combination with the drying-chamber, sealed atits bottom and sides, of a heating device located in said chamberadjacent to its bottom, an eductionpipe adjacent to the top of saidchamber having a series of apertures communicating therewith, anexhausting device connected with said eduction-pipe, and an air-pipeconnected with said eduction-pipe and having a portion lying adjacent tosaid heating device, substantially as described.

In testimony whereof we affix our signatures in presence of twowitnesses.

DAVID IIILL. JAMES S. IIILL.

Witnesses:

WILLIA E. PEARCE, JOHN W. DIXON.

IIC

